package lanqiao;

import java.util.Scanner;

public class 年号字串 {
    public static void main(String[] args) {
        int n = 2019;
        StringBuilder sb = new StringBuilder();
        while (n > 0) {
            n--;
            sb.append((char) (n % 26 + 'A'));
            n /= 26;
        }
        System.out.println(sb.reverse().toString());
    }
}
